TITLE: GCN CIRCULAR
NUMBER: 14139
SUBJECT: Short GRB 121226A: TNG observation of the host galaxy
DATE: 13/01/14 22:19:49 GMT
FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst
D. Malesani (DARK/NBI), P. D'Avanzo (INAF/OABr), A. Melandri
(INAF/OABr), S. Covino (INAF/OABr), A. Fiorenzano (INAF/TNG), L. Di
Fabrizio (INAF/TNG), and G. Andreuzzi (INAF/TNG) report on behalf of the
CIBO collaboration:
We observed the optical counterpart (Castro-Tirado et al., GCN 14114) of
the short GRB 121226A (Krimm et al., GCN 14105) with the TNG telescope
located in the Canary Islands. A total two hour exposure in the SDSS r
filter was acquired, with mean time 2013 Jan 11.227 UT (15.4 days after
the GRB). Sky conditions were good and the seeing was 1.1", despite the
large airmass (around 2).
Consistent with the position reported by Castro-Tirado et al. (GCN
14114) and Fong et al. (GCN 14126), we clearly detect an object with
r(AB) = 24.68 +- 0.15. Photometric calibration was carried out by
observing a standard field at similar airmass (for reference, we find r
= 19.35 for the USNO star at RA = 11:14:33.12, Dec = -30:23:51.2).
Coupled with the measurement by Castro-Tirado et al. (GCN 14114),
obtained ~0.5 days after the GRB, our observation suggests that the
object is the host galaxy of the GRB, with negligible afterglow
contribution at both epochs. We note that the radio detection (Fong et
al., GCN 14126) makes the association with the GRB secure.
The coordinates of the object as measured in our image are (J2000,
astrometry calibrated against USNO-B1):
RA = 11:14:34.125
Dec = -30:24:22.88
with an estimated uncertainty of 0.3". We note the presence of two
further, nearby objects, roughly 2" S and 4" NE of the optical/radio
counterpart. A finding chart is available at the following URL:
http://www.astro.ku.dk/~malesani/GRB/121226A/GRB121226A_finder_TNG.jpg